Patients with intracranial gliomas appear to have a deficiency of the immune response that is involved in the disease process. It is the purpose of this project to characterize the nature of this deficiency and its relationship to the course of the patient-host. Specifically, we are interested in demonstrating and isolating via physiochemical means the plasma factor(s) which inhibit the in vitro manifestations of cell mediated tumor immunity. The Plasma factor(s) will be categorized as to whether it inhibits both non-specific mitogen induced blast transformation and specific blast transformation in the mixed lymphocyte reaction. The degree of inhibition of mitogen induced lymphocyte transformation will be correlated to the clinical state of the patient and the malignant grade of the tumor in an effort to establish a prognostic scale.